Subsonic ammo?

Discussion in 'AR-15 Discussion' started by ccase39, Mar 10, 2014.

  1. ccase39

    ccase39 New Member

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    What is subsonic ammo vs regular? What are the benefits of something like a 300 blackout?


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  2. c3shooter

    c3shooter Administrator Staff Member

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    Subsonic (below sound) means that the bullet travels slower than the speed of sound. When a gun fires, there are two main components of sound- the BANG of gasses being released at the muzzle, and the CRACK of the bullet as it breaks the sound barrier.

    Subsonic, no CRACK. Used with a suppressor, rather quiet.

    When a supersonic bullet is fired, it has to STAY supersonic, or accuracy goes into the toity. As bullet falls below speed of sound, the shock wave that was trailing it moves up on the bullet, affecting the stability of the bullet (it wobbles). Most of the .22 MATCH ammo is subsonic all the way- problem solved. So are other rounds like Blackout, .45 ACP, etc.
     

  3. ccase39

    ccase39 New Member

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    So a subsonic bullet can be more accurate?


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  4. Mercator

    Mercator Active Member

    It depends on the gun, the cartridge, and the distance.
     
  5. sweeper22

    sweeper22 New Member

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    'Subsonic' can be a fine attribute when coupled with a suppressor. Without a suppressor, it has no value to me.

    It's just that simple...in my opinion.
     
  6. c3shooter

    c3shooter Administrator Staff Member

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    Agree with Mercator. One of my rifles is a .220 Swift. One load for that rifle is still at 1617 fps at 500 yards (sonic is roughly 1100 fps)

    Problem is most apparent when bullet changes from supersonic to subsonic. Either have one that will STAY above speed of sound, or use one that stays below- but keeps speed fairly constant.
     
  7. JonM

    JonM Moderator

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    Its the transition many hundreds of yards downrange that cause issues. For example 308 transitions subsonic around 1000-1200 depending on the bullet elevation and weather. Not many subsonic rounds reach out that far with any accuracy or power.

    At close range there is no advantage to sub vs supersonic rounds in unsuppressed applications.
     
  8. sweeper22

    sweeper22 New Member

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    Sorry...I coulda sworn this was the AR-15 board and a 300BLK specific question. So I was simply addressing rifle applications.

    45acp is fine. I have several. And of course I don't shop for 'supersonic' specific ammo when it comes to 45acp pistols, because there is very little of it to be had. Beyond a couple boxes of 165gr CorBon Pow'rBall, I doubt I own any.
     
  9. Pasquanel

    Pasquanel Proud to be an American Supporter

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    Many of us myself included simply check "today's post or new post" and from there its not easily apparent just which sub-forum you are in. I know I have inadvertently stomped on someones post from time to time its just the charm of the forum ;)
     
  10. Mercator

    Mercator Active Member

    I just had my wires crossed. Went back to edit but too late. My apologies.
     
  11. CGS

    CGS New Member

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    I bought a few boxes of sub sonic 9mm to test out if the felt recoil is reduced. If so, I'll be using it to train my newer students. It'll be interesting to see (feel) the results.